Practical Endgame Test 4 / Solution

4, 10 at marked stone; 7 at 1  

Seems to me that Black and White have six ko threats each.

Assuming Black takes the ko first...

(I think that White playing 8 instead of just continuing with 9 is one of the nice ideas in the problem. I know that I many times playing ko threats rather superficially without thinking of all alternatives. --DaveSigaty)

5 at marked black stone; 7 at marked white stone; 8 at 2  

(I think that finding Black 3 is the other really nice point of this problem. For me it is natural to play Black at 9 in such shapes automatically when looking for ko threats. --DaveSigaty)

 

... looks like Black wins. Any better answers, comments or objections?

-- unkx80